It is common practice in railroad and mass and/or rapid transit operations to constantly check the alertness of the locomotive engineer or trainman by requiring him to perform a certain repetitive task as the train moves along its route of travel. Presently, a pneumatic cycling valve is used in railroad applications as a means of requiring the train operator to periodically acknowledge his attentiveness by alternately activating a foot pedal spool valve device in order to suppress a penalty brake application. In requiring such periodic acknowledgement, the operator is unable to circumvent the safety system by simply placing a weight on the foot pedal valve to maintain it in a depressed closed position to provide a false indication of his watchfulness. However, the use of a pneumatic cycling spool valve type of vigilance safety control system entails moving parts and O-ring seals which are susceptible to wear and leakage problems. Thus, the previous cycling control systems not only were costly to manufacture and maintain, but also were relatively short-lived and troublesome.